Thermal Modeling of the Ground Surface for the Purpose of Calculating the Current-Carrying Capacity of Underground Cable Lines Using the FEM
Research Article  ·  Published: 27 March 2026
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ICCK Transactions on Electric Power Networks and Systems
Volume 2, Issue 1, 2026: 47-57
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Thermal Modeling of the Ground Surface for the Purpose of Calculating the Current-Carrying Capacity of Underground Cable Lines Using the FEM

1 Faculty of Technical Sciences, University of Priština in Kosovska Mitrovica, 38220 Kosovska Mitrovica, Serbia
2 Faculty of Technical Sciences, University of Kragujevac, 32102 Čačak, Serbia
3 Faculty of Electronic Engineering, University of Niš, 18104 Niš, Serbia
* Corresponding Author: Marko Šućurović, [email protected]
Volume 2, Issue 1

Abstract

In large-scale 2D finite element steady-state thermal models for underground cable ampacity calculations, where the lateral and lower boundaries are adiabatic, the ground surface may be represented by isothermal Dirichlet, convective Robin, or coupled convection–radiation conditions. In such cases, the soil temperature at depths significantly below the cables tends to be equal or to exceed the temperature of reference soil or air. This paper proposes a novel approach addressing this issue by dividing the native soil into two layers, introducing an effective thermal conductivity for the upper layer, and assuming distinct reference soil temperatures at the cable depth and at the lower boundary. The upper layer spans from the ground surface to the cable installation plane (where reference soil temperature is typically measured), while the lower layer extends to the domain’s bottom. For summer periods, the effective thermal conductivity of the upper layer is calibrated to correspond to measured reference soil temperature under the most unfavorable environmental conditions. A temperature equal to the local average groundwater temperature is assigned to the lower boundary. The study focuses on AXLJ 1×1000/190 mm$^2$ 110 kV cables in trefoil formation, installed in single- and two-layered native soils. Steady-state thermal analyses are performed using COMSOL 4.3. Results show that the cable ampacity can be increased by 8.43%, a value considered safe from both scientific and engineering perspectives.

Graphical Abstract

Thermal Modeling of the Ground Surface for the Purpose of Calculating the Current-Carrying Capacity of Underground Cable Lines Using the FEM

Keywords

current-carrying capacity finite element method (FEM) steady-state thermal modeling underground cable line

Data Availability Statement

Data will be made available on request.

Funding

This work was supported by the Government of the Republic of Serbia under Grant 451-03-34/2026-03/200155, Grant 451-03-34/2026-03/200132, and Grant 451-03-34/2026-03/200102.

Conflicts of Interest

The authors declare no conflicts of interest.

AI Use Statement

The authors declare that no generative AI was used in the preparation of this manuscript.

Ethical Approval and Consent to Participate

Not applicable.

References

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Cite This Article

APA Style
Klimenta, D., Šućurović, M., & Tasić, D. (2026). Thermal Modeling of the Ground Surface for the Purpose of Calculating the Current-Carrying Capacity of Underground Cable Lines Using the FEM. ICCK Transactions on Electric Power Networks and Systems, 2(1), 47–57. https://doi.org/10.62762/TEPNS.2026.891956
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Compatible with EndNote, Zotero, Mendeley, and other reference managers
TY  - JOUR
AU  - Klimenta, Dardan
AU  - Šućurović, Marko
AU  - Tasić, Dragan
PY  - 2026
DA  - 2026/03/27
TI  - Thermal Modeling of the Ground Surface for the Purpose of Calculating the Current-Carrying Capacity of Underground Cable Lines Using the FEM
JO  - ICCK Transactions on Electric Power Networks and Systems
T2  - ICCK Transactions on Electric Power Networks and Systems
JF  - ICCK Transactions on Electric Power Networks and Systems
VL  - 2
IS  - 1
SP  - 47
EP  - 57
DO  - 10.62762/TEPNS.2026.891956
UR  - https://www.icck.org/article/abs/TEPNS.2026.891956
KW  - current-carrying capacity
KW  - finite element method (FEM)
KW  - steady-state thermal modeling
KW  - underground cable line
AB  - In large-scale 2D finite element steady-state thermal models for underground cable ampacity calculations, where the lateral and lower boundaries are adiabatic, the ground surface may be represented by isothermal Dirichlet, convective Robin, or coupled convection–radiation conditions. In such cases, the soil temperature at depths significantly below the cables tends to be equal or to exceed the temperature of reference soil or air. This paper proposes a novel approach addressing this issue by dividing the native soil into two layers, introducing an effective thermal conductivity for the upper layer, and assuming distinct reference soil temperatures at the cable depth and at the lower boundary. The upper layer spans from the ground surface to the cable installation plane (where reference soil temperature is typically measured), while the lower layer extends to the domain’s bottom. For summer periods, the effective thermal conductivity of the upper layer is calibrated to correspond to measured reference soil temperature under the most unfavorable environmental conditions. A temperature equal to the local average groundwater temperature is assigned to the lower boundary. The study focuses on AXLJ 1×1000/190 mm$^2$ 110 kV cables in trefoil formation, installed in single- and two-layered native soils. Steady-state thermal analyses are performed using COMSOL 4.3. Results show that the cable ampacity can be increased by 8.43%, a value considered safe from both scientific and engineering perspectives.
SN  - 3070-2607
PB  - Institute of Central Computation and Knowledge
LA  - English
ER  - 
BibTeX Format
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@article{Klimenta2026Thermal,
  author = {Dardan Klimenta and Marko Šućurović and Dragan Tasić},
  title = {Thermal Modeling of the Ground Surface for the Purpose of Calculating the Current-Carrying Capacity of Underground Cable Lines Using the FEM},
  journal = {ICCK Transactions on Electric Power Networks and Systems},
  year = {2026},
  volume = {2},
  number = {1},
  pages = {47-57},
  doi = {10.62762/TEPNS.2026.891956},
  url = {https://www.icck.org/article/abs/TEPNS.2026.891956},
  abstract = {In large-scale 2D finite element steady-state thermal models for underground cable ampacity calculations, where the lateral and lower boundaries are adiabatic, the ground surface may be represented by isothermal Dirichlet, convective Robin, or coupled convection–radiation conditions. In such cases, the soil temperature at depths significantly below the cables tends to be equal or to exceed the temperature of reference soil or air. This paper proposes a novel approach addressing this issue by dividing the native soil into two layers, introducing an effective thermal conductivity for the upper layer, and assuming distinct reference soil temperatures at the cable depth and at the lower boundary. The upper layer spans from the ground surface to the cable installation plane (where reference soil temperature is typically measured), while the lower layer extends to the domain’s bottom. For summer periods, the effective thermal conductivity of the upper layer is calibrated to correspond to measured reference soil temperature under the most unfavorable environmental conditions. A temperature equal to the local average groundwater temperature is assigned to the lower boundary. The study focuses on AXLJ 1×1000/190 mm\$^2\$ 110 kV cables in trefoil formation, installed in single- and two-layered native soils. Steady-state thermal analyses are performed using COMSOL 4.3. Results show that the cable ampacity can be increased by 8.43\%, a value considered safe from both scientific and engineering perspectives.},
  keywords = {current-carrying capacity, finite element method (FEM), steady-state thermal modeling, underground cable line},
  issn = {3070-2607},
  publisher = {Institute of Central Computation and Knowledge}
}

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